From e12c836af7ebd3374cc6afb318308a0e18185291 Mon Sep 17 00:00:00 2001
From: vigneshakaviki <kumarvignesh295@gmail.com>
Date: Sat, 11 Apr 2026 15:18:05 -0700
Subject: [PATCH 1/2] test: add regression tests for scientific notation
 parsing (#284)

format() can produce scientific notation for very large values
(e.g. "5.696545792019405e+297y"), but parse() returns NaN for
these strings. Add tests that verify the roundtrip contract.
---
 src/index.test.ts | 7 +++++++
 src/parse.test.ts | 9 +++++++++
 2 files changed, 16 insertions(+)

diff --git a/src/index.test.ts b/src/index.test.ts
index 5035ab9..07a4170 100644
--- a/src/index.test.ts
+++ b/src/index.test.ts
@@ -327,6 +327,13 @@ describe('ms(number)', () => {
 
     expect(ms(-234234234)).toBe('-3d');
   });
+
+  it('should roundtrip format/parse for large numbers', () => {
+    const formatted = ms(Number.MAX_VALUE);
+    expect(typeof formatted).toBe('string');
+    const parsed = ms(formatted as `${number}`);
+    expect(parsed).not.toBeNaN();
+  });
 });
 
 // invalid inputs
diff --git a/src/parse.test.ts b/src/parse.test.ts
index 9182411..e904807 100644
--- a/src/parse.test.ts
+++ b/src/parse.test.ts
@@ -78,6 +78,15 @@ describe('parse(string)', () => {
   it('should work with negative decimals starting with "."', () => {
     expect(parse('-.5h')).toBe(-1800000);
   });
+
+  it('should work with scientific notation (roundtrip from format)', () => {
+    expect(parse('5.696545792019405e+297y')).not.toBeNaN();
+    expect(parse('1e3ms')).toBe(1000);
+    expect(parse('1.5e2s')).toBe(150000);
+    expect(parse('-1e3ms')).toBe(-1000);
+    expect(parse('1E3ms')).toBe(1000);
+    expect(parse('1e+3ms')).toBe(1000);
+  });
 });
 
 // long strings

From 5ee8bdfa4a8bcfd48db2cc77a2f127bd4073bb02 Mon Sep 17 00:00:00 2001
From: vigneshakaviki <kumarvignesh295@gmail.com>
Date: Sat, 11 Apr 2026 15:18:12 -0700
Subject: [PATCH 2/2] fix: support scientific notation in parse() for format()
 roundtrip (#284)

The parse() regex only matched standard decimal notation (-?\d*\.?\d+),
so values like "5.696545792019405e+297y" produced by format() for very
large numbers would return NaN.

Extend the numeric capture group to accept an optional exponent suffix
(e[+-]?\d+), matching what JavaScript's Number formatting can produce.
parseFloat() already handles scientific notation, so no other changes
are needed.
---
 src/index.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/index.ts b/src/index.ts
index d50e3c7..0796c11 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -75,7 +75,7 @@ export function parse(str: string): number {
     );
   }
   const match =
-    /^(?<value>-?\d*\.?\d+) *(?<unit>milliseconds?|msecs?|ms|seconds?|secs?|s|minutes?|mins?|m|hours?|hrs?|h|days?|d|weeks?|w|months?|mo|years?|yrs?|y)?$/i.exec(
+    /^(?<value>-?(?:\d*\.?\d+)(?:e[+-]?\d+)?) *(?<unit>milliseconds?|msecs?|ms|seconds?|secs?|s|minutes?|mins?|m|hours?|hrs?|h|days?|d|weeks?|w|months?|mo|years?|yrs?|y)?$/i.exec(
       str,
     );